Overshot tool



Dec. 16, 1952 B. F. WILEY OVERSHOT TOOL Filed Oct. 31, 1949 INVENTOR. B.F. WILEY ATTORNEYS F/GI.

Patented Dec. 16, 1952 @VERSHOT TOOL Bruce F. Wiley,- Bartlesville,Okla; assignor to PhillipsPetrolcum Company, a corporation of DelawareApplication October 31, 1949, Serial No. 124,714

Claims.

This invention relates to an overshot tool. In one of its aspects theinvention relates to an overshot tool which can be employed to place, orto remove, an object at a point deep in the ground, for example at thebottom of an oil well. In a more specific aspect the invention providesa tool which can .be lowered into a well down through which is extendeda cable, without the removal or cutting of said cable, to place or toretrieve an object in said well, for example a seismograph or a. wellinstrument. In an embodiment of the invention there is provided a toolwhich once assembled remains unitary at all times during its use but isadapted to receive into itself a cable, which may be attached to theobject to be placed into or retrieved from a well hole, by merelyoperating a rotatably sliding cylinder as set forth more fully below.

Overshot fishing tools are known in the art. One of these is soconstructed that it can surround a cable attached to the object or toolsought to be recovered. To this end the prior art tool is provided witha slot into which the cable can be threaded. The slot is provided with akey which covers, and retains the cable in, the slot. The key itself isretained by screws which pass through the said key and into the body ofthe tool. It is clear that in the use of the tool it is necessary toinsert the cable and then to place the retaining key in the slot andthen to drive home the screws which fasten the key to the body of thetool. Also, when the tool has been used to lift to the surface thedesired object the screws must be removed, then the key must be removedand finally the cable can be taken from the tool, unless the cable iscut in which event it will not be necessary to remove the key and thescrews which fasten it into position until another use is made of thetool. It is also evident that when screws are employed, these may becomeloose and drop out. In such event the key would also drop out or even bepushed out by the cable motion in the slot. Thus, a part of theretrieving tool would have to be itself retrieved from the hole orreplaced. Furthermore, unless the part of the retrieving tool which hasfallen into the hole is itself retrieved, it may hamper the originalretrieving operation. Also, it is to be noted specially that said priorart device is not employable to place and to release a cabled object ina well hole.

There is also known in the art a fishing tool comprising a bell-shapedhousing in combination with an expandable set of jaws located and urgeddownwardly therein by means of a compressible spring located between theupper portion of the bell and the upper portion of the-said jaws. As thebell portion is raised a beveled or seat portion around the inside ofthe bottom of the housing presses against the jaws .urging thesetogether whilethe said spring urges said jaws against said seat portionthus taking. hold of the pipe to be pulled. Such a fishing tool cannotbe employed toset into place in,..or to remove from, a well hole anobject to which is attached a cable, say a cable-suspended tool. Also,this prior art pipe puller cannot be employed readily to place an objectinto the bottom of a-well hole, although it is adapted to release a pipewhich is hopelessly stuck in the hole.

An object of this invention is to provide an overshot tool which canbeemployed to placeinto or to remove from a wellan object suchas-aseismograph, a well instrument or a cable-suspended tool.

Another object of the invention isto provide a unitary overshot toolwhich during its employment remains complete assembledor unitary.

further object of the invention is .to. provide an overshot tool theconstruction. features-of which are such that it does not have any partswhich, once the tool is assembled, prior to.-its employment, ,must be.removed and replaced, thereby ensuring that no part, orpartsgof. saidtool can become disengaged or disassembled, because ofan improperassembly, and dropintothe hole in which it is employed.

Further, still, it is another object of the invention to provide anovershot tool the construction features of which are such that itsassembly must needs be properly effected and when so effected no partthereof can become disengaged and drop into the hole in which it isemployed.

Other objects as well as advantages of the invention here presented areobvious from this disclosure, the appended claims and the drawing.

According to this invention there is provided an overshot toolcomprising in combination at least two slotted substantially cylindricaland concentrically disposed elements so adapted and arranged that theouter element is rotatably slidable upon the inner element and anovershot collet which is so adapted to and arranged with said elementsas to engage upon and to release a cabled object without cutting thecab-1e or otherwise removing it from said object.

Reference will now be made to the drawing in which is shown, in severalviews, an embodiment according to this invention. In the drawing Figure1 is an elevational cross-section view of the embodiment the cable beingshown in dotted lines. Figure'2 shows a transverse view taken along theline 2-2 of Figure 1. Figure 3 shows a transverse view taken along line33 of Figure 1 with the overshot collet and spring removed.

In Figure 1 the following elements or members of the tool are shown,support head 4 formed and threaded at its upper end to be engaged by acorrespondingly threaded pipe; supporting inner slotted cylinder 5fastened to support head 4 by means of screws 6 and provided with aflange I at its bottom end and inner .beveled seat 8; and groove 20which contains a slotted retaining ring I9; rotatably slidable andslotted outercylinder 9 which rests upon flange I; a spring III in a,vertical recess 23 in support head 4; collet II shaped at its upper endto spear into spring III in a manner such that motion of the supporthead 4 towards collet II will cause compression of spring I; slottedfingers I2 threaded with double buttress threads I3 and slotted as shownat I4; pins I5 fixed into inner supporting cylinder 5 and jutting intoslots I4 in a manner to prevent substantially any rotation of the colletand consequently its fingers I2 relative to supporting cylinder 5 butallowing motion of each finger I2 towards and away from said supportingcylinder; and the threaded upper end I6 of an object to be placed intoor recovered from a hole in the ground according to the objects of thisinvention. The object is one which is formed to receive a cable into itsupper bored end. The cable 24 is shown in dotted lines in this figure.

To assemble the tool spring I9 is placed upon collet H held in anupright position. This assembly is then placed into supporting cylinder5 the fingers I2 of collet II being pressed towards its longitudinalaxis to pass over and to engage the pins I5. Then outer rotatablyslidable cylinder 9 is placed upon inner supporting cylinder 5.Supporting head 4 is now lowered, over spring I9, until its shoulderedportion fits into inner supporting cylinder 5. By rotating outercylinder 9 until its slot is opposite each of the screw holes shown insupporting head 4 screws are then placed into position. When in use theslot in outer cylinder 9 is so placed that none of the screw heads isuncovered. To prevent undesired rotation of the outer cylinder about thesupporting cylinder there can be provided a tongue and groove, or balland socket, or equivalent means, on the outer surface of the innercylinder and on a surface of the outer cylinder. Thus, outer slottedcylinder 9 can have a short protrusion or tongue I"! and II which fitsinto a sloping groove I8 and I8 on inner slotted cylinder 5, so that aone half turn of the outer slotted cylinder 9 will jam its lower endagainst flange 7 thereby preventing any undesired rotation of thecylinder 9.

Thus it is that there is provided an overshot tool which has all of thefeatures and advantages set out in the object of this invention.

In operation, to lower a cabled object into a well, the slots in theouter and supporting cylinders are aligned, the cable 24 is threadedinto the interior of the tool and the outer cylinder is placed to itsclosed position following which the tool is pushed down upon the objectas shown in Figure l. The fingers I2 are spread apart and the doublebuttressed threads become engaged. At this stage the tool is pulledupwardly whereupon beveled seat 8 acts against fingers I2, the colletbeing urged downwardly, securing these to the object by means of therespective threaded portion of each. As long as the weight of the objectis supported by the tool the fingers I2 hold rigidly the object carriedby them. After the object has been lowered into position the tool isrotated to uncouple it from the object. It is to be noted that the cablepasses up through the center of the collet which holds the cabled objectconcentrically in its fingers. The cable then passes out through groove2| in the supporting head. A snap retaining ring I9 prevents the cablefrom becoming fouled. This ring I9 is in the form of a C and, before thecable is inserted, is positioned with the open part of the C in linewith the slot in cylinder 5. After the cable is inserted, ring I9 isturned so as to prevent reentry of the cable into the slot.

Holes 22 in the supporting head are provided in the tool for use in theevent that the object to be recovered has been buried by a sloughing oilof the walls of the well bore. In such use fiuid circulation can beestablished through the interior of the lowering tube (not shown) whichis fastened to supporting head 9. The force of fiuid through holes 22stirs up the sand and allows the tool to be lowered to the object.

Reasonable variation and modification are possible within the scope ofthe foregoing disclosure and the appended claims to the invention theessence of which is that an overshot tool, comprising in combination atleast two slotted substantially cylindrical and concentrically disposedelements so adapted and arranged that the outer element is rotatablyslidable upon the inner to enclose a cable and a collet which is adaptedto and arranged with said elements as to enable the tool to engage uponand to release a cabled object without cutting the cable or otherwiseremoving it from said object, has been set forth and its elements,assembly and operation described so as to enable one skilled in the artto assemble and to employ the same. Other applications of the mechanismof the invention will be apparent to those skilled in the art of likemachines.

I claim:

1. An overshot tool which comprises a support head; a spring receivingrecess in the lower end of said head; a longitudinal slotted hollowsupport body fixedly attached to said head; an outwardly projectingflange on the end of said support body opposite the point of attachmentof said body to said head; a longitudinally slotted, rotatably mounted,outer member positioned around said support body and retained thereon bysaid flange on said support body; an inner beveled seat in the endportion of said support body opposite the point of attachment to saidsupport body; a spring in said spring receiving recess in said head; anda collet comprising a plurality of fingers extending longitudinallywithin and with respect to said support body, said fingers being rigidlyconnected at their upper ends and disconnected at their lower ends, andbeing provided with connecting means for gripping an object to begripped by said tool at their lower ends, the upper end of said colletcontacting the lower end of said spring and being biased downwardly to aresting position on said inner beveled seat.

2. The tool of claim 1 wherein said connecting means comprises doublebuttressed threads.

3. The tool of claim 1 wherein at least one of said fingers is providedwith an opening therein; and the support body is fixed against rotationwith at least one element extending inwardly from its inner surfacepositioned so that said element protrudes into the opening in thefinger.

and the other of said members with a tongue 10 2,495,953

which extends into and cooperates with said groove so as to cause saidouter cylinder to move downwardly against said flange upon rotation in aproper direction.

BRUCE F. WILEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,610,699 Montgomery Dec. 14,1926 2,067,009 Hinderliter Jan. 5, 1937 2,249,358 Haynes July 15, 1941Austin Jan. 31, 1950

